T1048.001sub-technique of T1048 Exfiltration Over Alternative Protocol
Exfiltration Over Symmetric Encrypted Non-C2 Protocol
Linux · macOS · Windows · ESXinothing on this site yetT1048.001 on attack.mitre.org
Adversaries may steal data by exfiltrating it over a symmetrically encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server. Symmetric encryption algorithms are those that use shared or the same keys/secrets on each end of the channel.
If this is happening now
Checklists and playbooks to open while the alert is still live.
Playbook for this stage
Suspected data theft by an insider
A resignation with unusual file access, a DLP alert, or an unexplained large transfer.
how MITRE says to see it
Behavioral Detection Strategy for Exfiltration Over Symmetric Encrypted Non-C2 Protocol
- Detects the execution of non-browser processes establishing outbound encrypted network connections using uncommon symmetric encryption protocols (e.g., AES via PowerShell or custom scripts) to alternate external destinations.
- Detects command-line utilities or scripts using encryption libraries or symmetric algorithms (e.g., OpenSSL AES, GPG, Python + PyCrypto) in conjunction with outbound file transfers or traffic to external destinations.
- Detects symmetric key-based encryption operations (e.g., AES via Python, AppleScript, or OpenSSL) followed by unusual outbound connections from non-browser applications or scripted tools.
- Detects unexpected encrypted egress traffic from management services (e.g., hostd) or guest VMs utilizing symmetric encryption without traditional protocols (e.g., FTP with embedded AES ciphertext).
what reduces it
- M1031 Network Intrusion Prevention. Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary command and control infrastructure and malware can be used to mitigate activity at the network level.
- M1037 Filter Network Traffic. Enforce proxies and use dedicated servers for services such as DNS and only allow those systems to communicate over respective ports/protocols, instead of all systems within a network.
- M1030 Network Segmentation. Follow best practices for network firewall configurations to allow only necessary ports and traffic to enter and exit the network.